Speed control means for center pivot irrigation system
US4135539A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1978 |
| Grant date | Jan 23, 1979 |
| Priority date | — |
| Expiry date | Mar 27, 1998 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01G25/092
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for operating a center pivot irrigation system including a plurality of span units, each having a drive carriage having a hydraulically driven motor means for operating associated carriage wheels in response to hydraulic fluid supplied thereto under pressure through hydraulic fluid lines from a source thereof, is operated by supplying hydraulic fluid at a selectable value of constant volume fluid flow to the system to drive the system at a selectable average speed about its center pivot, the flow rate of fluid to individual motor means of individual span units which are ahead or behind of a predetermined relative alignment with the other span units being varied in response to changes in angularity sensed between adjacent span units in both forward and backward directions relative to the direction of travel of the system about its center pivot while the constant volume fluid flow through the system is being maintained at a selectable constant flow rate. An improved hydraulic adjustable rate flow valve accommodates fluid flow in reversible directions while maintaining close control or metering capabilities over the fluid flow through the valve in either flow di…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.